Long post, sorry. UOA at the bottom for the tl/dr folk. This was a very short interval between UOAs because I wanted to see if the high wear on the first one was still happening. Apparently it still is, at least it looks that way judging from the high wear metals after only 3 months. While 'testing margin of error' could account for some of it, it looks like higher wear in 1000 miles than what most people post after 4 times that. I had it gone over by a local certified shop, who found no reason for the high wear. They found some minor stuff (bad knock sensor, fan clutch that didn't always...clutch), but nothing to account for the unusual wear. I cut open the oil filter, and didn't see any tears, carbon bits, or metal flakes. Beyond that, I don't know what to examine in a used filter. There was quite a bit of good oil advice in my first UOA for this vehicle ( post 2385929 ) but no real consensus as to what the cause could be. So here's what I think: Vehicle Abuse! This wear level is likely explained by the mostly short trips this vehicle sees. Last year and this year, the norm has been short trips of 3-10 miles with at least an hour between them. This summer, most trips have been 2 -3 miles, with only a minute or two warming up time before moving out. Of the 1200 miles on this oil, probably 8000 was in 3 mile segments with an hour (or more) to cool down before the next trip. This winter looks like it will be even worse from a trip length perspective--almost exactly 2 miles per trip. However there should be fewer of them. I should only be driving this vehicle to work in the morning and home in the evening, with no trips during the day. So, here's what I plan to do. I'm going to do another very short OCI. For that I'm using a cheap synthetic: O'Reilly 0W-20 Syn ( post 2415164 ) because I don't want to spend a lot on really good oil I'm just going to dump in a few hundred miles. Now that it has turned cold (30 degrees this morning) my theory is the thinner the oil the better--maybe I'll get some lubrication out of it. I'll pull a sample in another 3 or 4 months and see if the wear has decreased any with the thinner oil. If it has, then I'll put in something good, Pennzoil Ultra probably. If not, then I'll be back here to explore the topic further. If all goes according to plan, this will be the last winter this poor pickup gets abused like this. Next year I'll (hopefully) be in an office 0.8 miles from home. With no need to carry my tools around, that's walking distance even in winter. Until then I'd like to minimize the damage, and I welcome advice anyone cares to give. Anyway, here's the UOA:
Originally Posted By: BlackstoneLabs
Wear dropped quite a bit in this second sample, but a lot of that is likely due to the much shorter oil run this time around. Still, we like the improvement, and until we can be sure of the cause of the high wear (or at least that it's gone away), we'd suggest staying with shorter oil changes like that. Silicon was the only increase; unless you've had work done to the engine recently, that may show dirt, so it wouldn't be a bad idea to check the air filter, and look for cracks or leaks downstream to see if any unfiltered air is getting in. That could cause high wear.
2000 Nissan Frontier 3.3L V6 with 54,000 miles on vehicle MI/HR on Oil 1,234 4,457 MI/HR on Unit 53,980 52,721 Universal Sample Date 10/17/11 06/25/11 Averages ALUMINUM 10 20 4 CHROMIUM 2 2 1 IRON 43 129 14 COPPER 5 14 4 LEAD 10 40 10 TIN 1 0 0 MOLYBDENUM 59 82 80 NICKEL 0 1 0 MANGANESE 1 3 1 SILVER 0 0 0 TITANIUM 0 0 0 POTASSIUM 2 7 5 BORON 15 103 44 SILICON 17 16 11 SODIUM 8 19 38 CALCIUM 2364 3159 2219 MAGNESIUM 11 23 119 PHOSPHORUS 764 892 682 ZINC 850 1056 829 BARIUM 0 0 0 PROPERTIES 10/17/11 06/25/11 Should Be SUS Viscosity @ 210°F 59.3 60.5 54-61 cSt Viscosity @ 100°C 10.02 10.35 8.5-10.8 Flashpoint in °F 385 360 >365 Fuel % <0.5 TR <2.0 Antifreeze % 0.0 0.0 0.0 Water % 0.0 0.0 0.0 Insolubles % 0.3 0.4 <0.6